ABSTRACT
The western interior of North America contains large, arid, and semiarid regions that represented challenges for human adaptation. American Indians of the Interior West relied primarily on hunting and gathering for most of prehistory. A series of long fluctuating hot and dry climatic episodes scorched the region for millennia, selecting for highly mobile lifeways. Over the last two millennia of prehistory, favorable conditions promoted the spread of farming into the Great Plains up river valleys from the Eastern Woodlands and into the Great Basin from the Southwest. Residents of the Plateau region adapted in some ways that were similar to groups living along the Northwest Coast. Significant archaeological sites of the Interior West include dry caves, buffalo (bison) jumps, and formations with rock art. Horses brought to the region by Spanish colonists from the Southwest were incorporated by Native communities, resulting in nomadic Plains Indian tribes. The Lewis and Clark expedition of 1804–1806 encountered these tribes and those living in permanent agricultural towns along the Missouri River. Farther west, American Indian communities were documented on the Plateau. Descendants of all of these nations survive today in the region.
